Esters, and process for making the same



Patented June 19, 1934 UNITED STATES PATENT. OFFICE ESTERS, AND PROCESS FOR MAKING THE- SALIE James H. Wernt l, Wilmington, DeL, assignor to E. I. du Pont dc Nemours & Company, Wilmington, Dcl., a corporation of Delaware No Drawing. Application August 4, 1932,

. Serial No. 627,459

24 Claims. (Cl. 260-2) This invention relates to new compositions of matter, and more particularly to new compositions of matter which are capable of forming both resinous and rubber-like materials; and still more 5 particularly to new compositions of matter which result from the chemical combination of monovinylacetylene with organic acids, and to the polymers of these new compositions of matter.

This invention has as an object the production of organic carboxylic esters of 113 butadienol-Z,

Organic esters of 1,3-butadienol-2 are new' compounds as a class. They are readily polymerized to form polymers having wide and varying properties, and capable of extensive use in the arts.

The general method of preparing these novel organic esters comprises reacting monovinylacetylene with an organic acid in the presence of a suitable catalyst.

Vinylacetylene, a hydrocarbon having the structure CH =CHC CH,

has been prepared by Willstatter and Wirth (Ber., 4 Vol. 46 p. 535 (1913)). It has been prepared according to a different method by Nieuwland (U. S. Patent No. 1,811,959), and by Calcott and Downing (U. S. patent application Serial No.

303,494, filed January 6, 1928) the polymerization of acetylene being carried out in the presence of a catalyst composed of a cuprous salt, metallic copper, a salt of a tertiary amine or ammonia, and water, and/or suitable acids. Thru the agency of this catalyst medium, acetylene is 5 caused to react with itself to produce a number of polymers, one of which is vinylacetylene. The

vinylacetylene may be readily separated and purified by fractional distillation.

The following examples which are illustrative only and which are not to be construed as limiting the scope of the invention describe preferred procedures for making the organic esters of butadienol:

Eata'mple '1-Preparation 0) 1,3-butadierti1l-2- acetate Butadienyl acetate was made by adding monovinyl acetylene to glacial acetic acid containing mercuric sulfate as a catalyst. The apparatus consisted of a one liter 3-neck flask provided with a high speed stirrer (2000-3000 R. P. M.). The

blades of the stirrer were so constructed as, to

secure very intimate mixing of all the components of the reaction mixture. A thermometer was inserted in the rubber stopper which supported the bearing of the stirrer to record the temperature of the reaction mixture. The monovinylacetylene was placed ina calibrated dropping funnel which was jacketed with a solid carbon dioxide-acetone mixture. The exit tube of the dropping funnel extended thru one'neck to the bottom of the flask and was held in position by means of a rubber stopper. thru which ice water was circulated was attached to the other neck of the reaction flask by means of a. rubber stopper. The reaction mixture was vented thru the reflux condenser by a tube which led .into a trap cooled with a solid carbon dioxideacetone mixture. This'trap permitted collecting and measuring the monovinylacetylene which was not absorbed by the reaction mixture. The

A reflux condenser reaction flask was surrounded by an ice-salt bath after the reaction had started.

Ten grams of mercuric oxide was dissolved in 200 g. of hot glacial acetic acid and the solution was placed in the reaction flask and cooled to room temperature. Ten grains of acetic anhydride was then added to the reaction mixture and the stirrer started. To the rapidly agitated solution, four grams offuming sulfuric acid was next added drop by drop.- Mercuric sulfate was thus formed in a finely divided condition. One hundred seventy-three grams of liquid mono-' vinylacetylene was then placed in the calibrated dropping funnel and introduced into the agitated reaction mixture. add this amount. The temperature at the start of the reaction was. 12 C. and was dropped to It required about 1.5 hours to 0-5 C. in about 15 minutes by means of the ice bath where it remained thruout the experiment.

Practically all the monovinylacetylene-was absorbed by the reaction mixture at ice bath temperatures. The reaction mixture was poured into Example 2-Preparation of 1,3-butadienvl-2-..,

acetate Twenty grams of mercuric oxide was dissolved in 4.00 grams of hot glacial acetic acid; the solu tion was placed in the apparatus described in Examle l and cooled to 20 G Twenty grams of sulfo-acetic a'cidwas made by mixing 10 grams of fuming sulfuric acid with 10 grams of acetic anhydride cooled by means of an. ice bath and was added slowly to the rapidly agitated mercuric oxide solution. Twentygifams of acetic anhydride was then poured into'the reaction mixture and finally 8 grams of fuming sulfuric acid was added drop by drop. The reaction mixture was then cooled to 1%" C. andiilil grams of monovinylacetylene was added as liquid tothe rapidly agitated reaction mixture during the course of 4 hours. The reaction temperature was dropped to 5 C. in about half an hour where it was held during the reaction by'means of an ice bath.- The reaction mixture was poured into water saturated with salt, the water insoluble layer neu tralized with ammonium hydroxideand finally washed with saturated salt solution. After dry= ing over calcium chloride the product was fractionated under reducedpressure and 80 grams of crude butadienyl acetate boiling ao-ao C. at 20 mm. was obtained which amounted to a yield of 10.7%, based on the acetic acid used. Refractlonation of the crude butadienyl acetate yielded f '43 g. boiling 3340" c. at 20 mm. Sixty-four grams of resin was isolated from the reactiom mixture. The resin was soluble inacetic acid but became substantially insoluble in all solvents when heated. V

Example 3-Preparation of 1,3-butudienyZ-2- enter-acetate.

I Five moles of chloracetic acidand 10 grams of mercuric phosphate were placed in a 3-neck flask equipped with a stirrer, reflux condenser, and inlet tube leading to the bottom. The reaction mixture was then vigorously stirred while 4 moles of monovinylacetylene was bubbled in as gas during 5 hours. Three grams of catalyst-were added after the first, second and hour. The temperature dropped slowly 2 71 C. at the start to 57 (Lat the end of the rmction, Three moles of the monovinylacetylene. were absorbed. The reaction mixture was a e rapidly at 15 until only chloracetic acid distilled. The distillate was chilled with ice and the chloracetlc acid which crystallized was filtered oil; The fll= trate was washed with water and with dilute am.- monium hydroxide until neutral. After :1,

over calcium chloride the material Wild several times and finally 5 grams was obtained which boiled constantly at 5143 C. at 72 mm. The yield was about 1% based on the acid. used. A large amount of the ester converted to polymer during the reaction and suuent distillations. 1

Example 4.--Preparatiqn a; .ns-bctyz -z Two hundred thirty a. (5 moles)v of dry formic acid and zoo g. or gasoline which, boiled at 50 C. at 10 mm. were placed in a three necked flask equipped as descri in Example 3. Twenty-three gr oi. mercuric phosphate were used as the catalyst; ten were added st the start, 8' after the .hour and 5 grams after the second hour; Thereaction, mlx= ture was vigorously agitated and zoo grams is. moles) of monovinylacetylene as gas was allowed to bubble into the reaction during at hours. temperatur about 50 Q. I a

' 17.6 grams of mercuric oxide, 7.8 grams of fumone was'added to the reaction mixture audit was distilled at mm. The portion distilling below 100 C. at this pressure was collected. The distillate separated into two layers. The upper layer proved to be only the aliphatic diluent that was used in the reaction. The lower layer was neutralized and salted out with a potassium carbonate; solution. After drying over potassium carbonate the liquid was refractionated a number of times over 'hydroquinone and finally 21 grams boiling 48-49 C. at 31 mm. was isolated. This amounted to a yield of 4%. An appreciable quantity of resin formed during the reaction and during distillation of theproduct.

Example 5.Prcparction of 1,3-butadienyl-Z- butyrate Three hundred fifty=twc grams of butyric acid,

ing sulfuric acid, 17.6 grams of sulfo-acetic acid, 17.6 grams of acetic anhydridewere placed in a three neck flask equipped as described in Exple 3. The mixture was. rapidly stirred and the temperature was maintained atoll-55 C. during 1 the, reaction. Two hundred eight grams of monovinylacetylene as gas was bubbled into the reaction mixture during 4 hours. One hundred seventy-three grams of the monovlnylacetylene was'ab'sorbed during the reaction. The reaction mixture was distilled under reduced pressure and the distillate was washed and neutralized with a saturated potassium carbonate solution. The liquid was dried over anhydrous potassium car'- bonate and refractionated a number of times over 10 hydroquinone. Twelves gramsol liquid was obtained which boiled 59-60" (L at ll mm. A large amount of the ester polymerized during the reaction and during purification. I

The butadienyl esters are made-by cai'alyticallyv 5 reacting monovinylacetylene either as gas or liqv uid with an organic acid which is preferably in the liquid state, i. e., the acid is either normally liquid or if it is normally a solid it is a...

in a suitable solvent. The concentration of acid 339 the yield of crude butadienyl acetate b on the acetic acid used is 2.5% while at 0 or25 C.'the

yield is about 20%. When the cond i tion of 139 monovinylacetylene with acetic acid is carried out at 50 C. about 9% of butadienyl acetate and 9% of a diacetate of butenediol are obtained. A nonrcac tive diluent, such as an aliphatic 1 bon, can be used for better controlot the re- 335 action. For example, when a high boiling gasoline is used as a diluent-at 50 C. an 8% yield of crudebutadienyl acetate is obtained and no higher boiling unsaturated material is formed.

The prortions of monovlnylacetylene and 140 organic acid can vary considerably above and -.below equlmolecular proportions, although approximately equimolecular proportions are prezierred; As illustrating the use of an excess of monovinylacetylene. when one mole of acetic acid con mercuric sulfate as a catalyst is introduced into moles of monovlnylacetylenc a. 2% yieldcf butadienyl acetate is obtained.

id stirring is preferredduring the ester- $1 reaction, b m r the resetresults.

The preferred catalyst mixture consists of inercuric sulfate, sulfo-acetic acid, and acetic anhydride. Under comparable conditions a 10% yield of butadienyl acetate is obtained with this catalyst mixture while with mercuric sulfate alone a yield of 3.5% is obtained. Benzene sulfonic acid can be substituted for sulfo-acetic acidv in the catalyst mixture. Ferric sulfate, copper sulfate or other oxidizing agents such as vanadates, chromates, manganates, etc., can also be used in the catalyst for the reaction in admixture with mercuric sulfate or in admixture with other suitable catalytic mercury salts. Mercury salts other than mercuric sulfate can also be used, for example, a 4% yield of butadienyl formate is obtained from formic acid and monovinylacetylene with mercuric phosphate as a cat alyst. Other mercuric salts in which the mercury atom is directly attached to oxygen, e. g., mercuric nitrate, mercuric benzene sulfonate, mercuric sulfo-acetate, etc., or other mercuric salts of non-carboxylic acids may be used. Mercuric salts in which the mercury is linked directly to carboxyl, e. g., the acetate are not highly emcient catalysts. Boron trifluoride is a catalyst for the condensation. 'In one case its use led to the formation from monovinylacetlyene and acetic acid of 6% of butadienol acetate and 15% of a diacetate of butenediol. Alkali metal bisulfates, e. g., potassium bisulfate may also be added to the mercury catalyst mixture. The proportions of thecatalysts in'the mixture can be varied from those disclosed in the examples, but the presence of .too great an amount of catalyst results in the formation of polymers of the formed esters. Thus, twice the usual 'quantities of catalysts have been used and have 'water saturated with sodium chloride, (d) dry- .diene.

astea'm distillation or 'a' combined vac steam distillation. The reaction mixture 0' poured into water, the water insoluble liquid moved and distilled. antioxidant such as hydroquinone or pyrogallic acid-can be useddur ing the distillations. The preferred procedure for isolating the unpolymerized esters of the lower molecular weight fatty acids consists in (a) separating the water insoluble oily material by washing the reaction mixture with water saturated with sodium chloride, (b) neutralizing the unreacted organic acid in the water insoluble material with ammonium hydroxide, (c) washing out any excess of ammonium hydroxide with ing with calcium chloride or someother drying agent, and (e) fractionating under reduced pressure. I

The boiling range, 3840 C., at 20 mm. of the butadienyl acetate indicates it to be a monoester since the diacetates of butenediol that are described in the literature all boil above 'C. at 20 mm.- -When butadienyl acetate is heated with aqueous sodium hydroxide solution, practically all the material is converted to a brittle, thermoplastic, water-insoluble resin. No methyl vinyl ketone, the tautomer of 1,3-butadi'enol-2, can be detected in the distillate secured upon distillation of the.hydrolysis mixture with steam. On the other hand, the hydrolysis of butadienyl acetate with dilute hydrochloric or sulfuric acids yields, in addition to a soft. water-'insolub1e resin, a product which. distills with steam. This product may be converted to a solid pyrazoline derivative by reaction with phenyl hydrazine. It melts at 7576 C., the melting point of the same derivative of methyl vinyl ketone. Analytical results obtained for this pyrazoline are carbon 73.7%, hydrogen 7.6%; calculated for methyl-3- phenyl-l pyrazoline, carbon 75%, hydrogen 7.5%.. This evidence indicates that the acetate radical is attached to the second carbon atom in buta- The physical constants and'analytical data forsome of the butadienyl esters are given of resin the reaction mixture can be heated at. t M 50-100 C. in an open or closed container for m the appenfied several hours at the end of which time little The organic esters of butadenol may bemade distillable material remains. If desired, an antiby h statlc and commuous processesoxidant, like hydroquinone, may be in in under moreased pressure or under1educed presthe reaction mixture'to suppress polymerization. m and atltempelalimes ranging fIOm 5.0-; W The resin can be isolated from the reaction mix- At h 10 Wer p r u e ea t n ture or from its solutions by precipitation with goes y Slowly W e t t l her temperature alcohol or by removal of the solvent by distilpolymerization takes pla l s e v y: lation. Higher temperatures also favor formation of di- I,

I The unpolymerized esters may be recovered in esters of butenediol.

Physical constants and analytical data for some butadienyl esters Analyses Refrac- Moi. wt. (in Boilin Molecular repoint? G ggg {ractivity Ch] "wig-gen Butadienyl ester Carbon Hydrogen orme "0. mm. dig" up" gfigf' Found Calc'd Found Calc'd' Found Calc'd Found Calcd Found 51 0.9760 1.4530 26.2 27.2 01.2 02.9 0.1 0.7 9s 04 40 0.905s 1.4433 30.8 .30.7 04.3 62.8 7.1 7.2 112 100 2 1.1095 1.4783 35.7 35.4 24.2 24.0 11 0.03 0 1.4413 450.0 30.5 68.6 06.6 as as 140 13s Calculated [or mono-ester; calculated for di-acetate C, 55.8; 11,6.97; M.W., 172; calculated for dl-butyrate C, 63.21, 8.77; M.W., 228.

a number of ways from the reaction mixture. They can be distilled directly from the reaction mixture, preferably under reduced pressure, or the product can be separated from the resin by The above description and specific examples have dealt particularly with the production of 1,3-butadienyl-2 esters of. monobasic aliphatic carboxylic acids However, they scope of the in- 'use in the present invention correspond to the ever, it may likewise be applied to the formationof esters under the same general reaction conditions by the addition of organic acid to the following compounds which may be usedin lieu of vinylacetylene: v v

(1) Vinyl acetylides of the general formula CH2: CH-C 5 CR in which R represents an organic radical, e. g., alkyl or aryl. These compounds and their methods of preparation are disclosed in Carothers and Jacobson Application Serial No. 574,359, filed November 11, 1931, one method of preparation comprising the interaction of vinylacetylene with sodamide, the resulting sodium vinyl acetylide being then reacted with an alkyl chloride to pro-' duce the alkyl or' aryl vinyl acetylide.

(2) Vinylacetylenes having the general formula in which R is an organic radical, e. g., alkyl or aryl. These compounds and their method of preparation are disclosed in Carothers and Coffman Application Serial No. 569,832,. filed October 19, 1931,, one method of preparation comprising the interaction 'of an aliphatic or aromatic aldehyde or ketone, acetylene and sodam ide, then catalytically dehydrating the formed carbinol by passing over a dehydrating. catalyst at about C.

Vinylacetylene and its derivatives suitable, for

formula:

CH2 E CR1 in which R and R1 are hydrogen or organic hour).

radicals.

The organic esters of butadienol polymerize spontaneously although polymerization is accelerated by'heat, pressure, light, andv by catalysts such as mineral acids, alkalies, organic peroxides, inorganic peroxides, ozonized turpentine or stannic chloride. Polymrizationalso takes place in the presence of mineral acids, alkalies or monobasic acids under the influence of heat or pressure. Heat for example has a marked effect on the rate of polymerization of butadienyl acetate. In a solution containing equal parts of the ester and an, aromatic hydrocarbon, 7.5% polymerization is obtained in 4 days at room temperature or in 1 hour at C. as compared with 37% polymerization secured in 1 hour at 145 C. The formate, chloracetate, and butyrate esters polymerize slowly at room temperature; when heated at 100 C. with benzoyl peroxide for an hour they become very viscous. Benzcyl peroxide catalyzes polymerization at room temperature; at 100 (2. the catalytic effect is even more marked (72% polymerization of butadienyl acetate in one Stannic chloride catalyzes polymerization-of the esters at room temperature to yield dark colored resins. When butadienyl acetate is heated with aqueous alkali a hard, brittle resin which melts without decomposition is obtained;

captans and thiocarbamates.

when heated with dilute hydrochloric or sulfuric acids soft, water-insoluble resins are formed. Sunlight accelerates the rate of polymerization of the esters.

of butadienyl acetate is obtained in one week. Pressure has a marked effect on the rate of polymerization. For example, butadienyl acetate containing an antioxidant such as pyrogallol yields 72% of rubber-like polymer when subjected to a pressure of 5000 atmospheres for 17.5. hours at 57 C.

1-3-butadienyl-2 acetate and the other corre- 'sponding esters polymerize readily when heated in solutions such as in acetic acid or in toluene.

The polymer canbe isolated by precipitation with alcohol or by removal of the solvent under reduced pressure. Polymerization can be effected in the presence of a solvent for both the monomeric ester and the polymer, such as acetic acid, and in the. presenceof an inert solvent for the unpolymerized material which is a non-solvent for the polymer such as alcohol. Polymerization takes place in the presence of aninert solvent for the original material and the polymer such as gasoline, in the presence of a polymerizable solsuch as the ammonium or alkali metal salts of organic acids of high molecular weight, for example of the higher fatty acids, of resin acids such as abietic acid, or aromatic sulfonic acids, such as those obtained by the reaction of naphthalene, acetone, and sulfuric acid, and of complex acids, such as those formed by partial esteriflcation of dibasic acids with polyhydric alcohols which are themselves partly esterified with monobasic acids. Salts of these acids with metals, other'than the alkaline metals, may also be used in some cases. The organic esters of butadienol may be emulsifled in acetic acid containing casein or tothe einulsions, made with sodium oleate for example, casein may be added before acidifying with acetic .acid.

The butadienyl esters when exposed to even a small amount of air polymerize at room temperature to form rubber-like polymers in ten days to two weeks time. Blanketing with oxygen-free. gases such as carbon dioxide or nitrogen, and introducing small amounts of antioxidants all retard polymerization. Examples of such antioxidants include phenolic compounds like hydroquinone and pyrogallic acid, halogens such as iodine or bromine, nitro compounds like trinitrobenzene, amines likev phenyl beta naphthylamine, and sulfur and sulfur compounds such as mer- The rate of polymerization of the esters may be retarded by the presence of compounds containing activated double. bonds adjacent to carbonyl groups such as benzoquinone, naphthoquinone, maleic 'andfumaric acids, maleic and fumaric anhydrides, maleic and fumaric esters, methyl vinyl ketone which compounds are capable of reacting with the'unpolymerized esters.

Polymerization of the esterseither alone, or

in solutions or suspensions can be effected in the When uranyl nitrate is present during exposure to sunlight 89% polymerization 1,963,108 presence of drying oils, such as linseed or China-- wood oil or their acids, in the presence of semidrying oils, such as olive and caster oils or their acids, and mineral oils such as liquid petrolatum. Polymerization of the esters can be carried out in the presence of natural resins such as Congo, damar, kauri, rosin, ester gum or shellac or in the presence of cellulose derivatives such as cellulose nitrate, cellulose acetate or ethyl cellulose, and in the presence of synthetic resins, for example, phenol formaldehyde, glyptal, urea formaldehyde, styrene, and vinyl resins. Polymerization can be carried out in the presence of softeners or plasticizers such as camphor, glycerol, benzyl phthalate, arylphosphates, alkyl phthalates, and Vaseline.

The organic esters of butadienol form three types of rubber-like polymers, depending on their method of preparation. These types may be designated resin polymer, rubber polymer and latex polymer. The resin polymer is the soluble polymer which results when the esters are polymerized in solutions, polymerization being stopped before the insoluble stage is reached. Their solutions give clear homogeneous films when the solvent evaporates. The rubber or less soluble polymer is formed when the esters polymerize in the absence of a solvent or when .poly- I merization is carried out in a solvent until the polymer becomes insoluble. The latex polymer is formed when polymerization is carried out in emulsions. The resin polymer is probably converted to the rubber polymer on further polymerization. The latex polymer resembles vulcanized natural rubber. Both the resin and the rubber polymers may under certain circumstances be converted to a material resembling vulcanized natural rubber. I

.Butadienyl esters when heated in the absence of a solvent or when let stand at room temperature for several weeks form a material which resembles rubber, and which toughens on aging. The rubber polymers of the chloracetate ester are tougher and more elastic than those of the acetate and formate esters. Solutions of the resin polymer of the acetate give clear, colorless films which do not wrinkle while drying and are soft and flexible. The films discolor only slightly when exposed to ultraviolet light for 12 hours or to sunlight for several days. Films of the acetate resinpolymer made at 145 C. dry tack free in two to three hours. The resin polymer of the acetate is compatible in mixtures with pyroxylin in equal proportions but only to a limited extent with cellulose acetate, polyvinyl acetate, linseed or China wood oils. The resin polymer of the formate ester is insoluble in toluene, differing in this respect from the acetate and chloracetate esters. Films of the resin polymer of the formate dry more rapidly (tack-free in 30 minutes) than those of the acetate or chloracetate, polymers. The latex polymer of the esters. for example, of the acetate, formed by emulsifying with water resembles a vulcanized natural rubber in being somewhat elastic.

The polymers, interpolymers, and cross polymers of the esters may be employed in coating or impregnating compositions for wood, stone, leather, cloth, paper, metal, rubber,-glass, and synthetic resins. They may be used as clear finishes or with pigments in enamels. The pcly-' mers may be mixed with wood flour, ground cork or mineral filler for use in plastics. They may be used in laminated products as a binder for sheets of cellulose acetate, pyroxylin, or glass.

The polymers may be used as adhesives for woodpz n stone, leather, cloth, paper, metal, rubber, glassy." or regenerated cellulose film. Films of the latex. polymer may be formed by flowing, dipping or electrodeposition, or the latex may be extruded intoa coagulating bath to form sheets or fibers. The polymers may be used in compositions repre-' senting combinations withcellulose derivatives such as cellulose nitrate, the natural gums or resins, with synthetic resins, with softeners or plasticizers, with pigments, bituminous materials, with oils such as the drying and semi-drying oils, with antioxidants, and with dyes.,

The above description and examples are illustrative only and are not to be construed aslimiting the scope of the invention. Anymodification or variation therefrom which conforms to the spirit of the invention is to be included within the scope of the claims. i

I claim:

1. As new chemical'compounds, the additio products of an organic carboxylic .acid and a compound having the formula in which R and R1 are hydrogen or organic radicals.

2. As new chemical compounds, the 1,3-buta-' dienyl-2 esters of organic carboxylic acids.

3. As new chemical compounds, the 1,3-butadienyl-2 esters of aliphatic carboxylic acids.

4. As new'chemical compounds, the 1,3-butadienyl-2 esters of saturated'monobasic aliphatic carboxylic acids.

5. As new chemical compounds, the polymers 0 of the addition products of an organic carboxylic acid and a compound having the formula CH;=CRC CR,

in which R and R1 are hydrogen or organic 5 radicals. 3

6. As anew chemical compound, 1,3-buta- 'dienyl-Z-acetate.

7. As new compositions of matter, the polymers of the 1,3-butadienyl-2 esters of organic carboxylic acids.

8. As new compositions of matter, the polymers of the 1,3-butadienyl-2 esters of aliphatic carboxylic acids.

9. As new compositions of matter, the polymers of the 1,3-butadienyl-2 esters of saturated monobasic aliphatic carboxylic acids.

10. As new compositions of matter, the .polymers of 1,3-butadienyl-2-acetate. I

11. The process of forming esters which comprises reacting an organic carboxylic acid and a compound having the formula CHz=CRC CR,

' zene-sulfonate, and boron trifluoride.

19. The process of forming esters which comprises reacting vinylacetylene with saturated monobasic aliphatic carboxylic acids in the liquid state, said catalyst comprising essentially mercuric sulfate and a member of the group consisting of sulfa-acetic acid and benzene sulfonic acid. 20. The process which comprises commingling vinylacetylene, glacial acetic acid and mercuric sulfate, agitating the mixture and removing the formed Lii-butadienyl-Z acetate from the reaction mixture.

21. The process which comprises polymerizing an addition product of an organic carboxylic acid and acompound having the formula in which R and R1 are hydrogen ororganic radicals.

22. The process which comprises polymerizing a 1,3-butadienyl-2 ester oi an organic carboxylic acid;

23. lI'he process which comprises polymerizing a 1,3-butadienyl-2 ester of an aliphatic carboxyli c acid.

24. The process which comprises polymerizing a 1,3-butadienyl-2 ester of a saturated monobasic aliphatic carboxylic acid.

JAMES H. WERNTZ; 

